The Echoes Storm

A legendary and near-mythic pirate ship that sank hundreds of years ago but still is rumoured to appear with a storm in it's sails and it's captain standing at the helm summoning clouds and lightning with his legendary Soul Arm.
According to rumour, the echoes storm has wandered the seas and storms for millenia and is allegedly the first boat of humanoids, used to do battle with Gods during the first sundering.